"TokuMX is a drop-in replacement for MongoDB, and offers 20X performance improvements, 90% reduction in database size, and support for ACID transactions with MVCC."TokuMX introduces patented Fractal Tree indexing technology (Technology Overview in PDF), which improves upon MongoDB's default B-tree indexing. Fractal Tree indexing is based on cache-oblivious algorithm and it implements the same operations as a B-tree. Fractal Tree indexes uses large, less frequent writes instead of small and rapid ones, which gives a benefit for compression and insertion performance.
Key features overview:
Recently Tokutek released TokuMX version 1.4, which brings us improvements to MongoDB sharding and replication among other useful features. For more information on this release, please, check out full release notes.
TokuMX open-source engine can be found on Github as Tokutek/mongo (GNU General Public License). There is also an Enterprise version with proprietary EULA. To obtain Enterprise version, a subscription must be purchased. It gives customers the following benefits: Technical Support, Onboarding Call and access to Advanced Tools (e.g., Hot Backup).
Product homepage - TokuMX
TokuMX is MongoDB on steroids (MySQL Performance Blog)